Hantavirus
Hantavirus is a Notifiable Condition.
What is Hantavirus?
Hantavirus is a rare but serious virus spread by infected rodents, especially deer mice. In Washington State, deer mice are the only known rodents that carry hantavirus.
Hantaviruses are a family of viruses which can cause serious illness and death. The virus can cause a severe lung infection called Hantavirus Pulmonary Syndrome (HPS) or hemorrhagic fever with renal syndrome (HFRS). The Andes virus, a type of hantavirus that is native to South America, is the only type of hantavirus that is known to spread person-to-person. Sin Nombre virus is a common type of hantavirus found in the western United States.
Although uncommon, it can be very serious and may require hospitalization. About one in three people diagnosed with HPS die from the illness. HFRS is more commonly diagnosed among people in Europe and Asia.
How does Hantavirus spread?
People usually become infected by breathing in tiny particles contaminated with rodent urine, droppings, saliva, or nesting materials. This most often happens when cleaning or disturbing areas where mice have been active.
You can also be exposed by:
- Touching contaminated materials (nests, feces) and then touching your eyes, nose, or mouth
- Being bitten by an infected rodent (rare)
In Washington State, the type of hantavirus found in deer mice does not spread from person to person.
Symptoms of HPS usually begin two to four weeks after exposure but can appear anywhere from one to eight weeks. Early signs of illness include mild, flu-like symptoms such as:
- Fever
- Muscle aches
- Fatigue
- Headaches
- Dizziness
- Chills
- Abdominal problems such as nausea, vomiting, diarrhea, or stomach pain
As the illness becomes more severe, symptoms can include:
- Coughing
- Shortness of breath
- Trouble breathing
- Fluid buildup in the lungs
People with severe symptoms often need hospital care right away.
Who is at greater risk?
People may be at higher risk if they:
- Clean in cabins, sheds, garages, barns, cars or outbuildings with rodent infestations
- Work in, camp, or spend time in rodent-infested areas
- Touch rodent droppings or nesting materials
How can I protect myself?
Prevent rodents from entering buildings
- Seal holes and gaps larger than ¼ inch
- Store food, including pet food, in rodent-proof containers
- Keep areas cleans and free from clutter
- Ask a pest control company for help
If you have a rat problem in your neighborhood, please report it on our Contact Us Form online. We will send informational postcards, or “rat cards,” to nearby homes to help residents identify and address conditions that may contribute to growing rat populations.
Rodents may enter vehicles through rust holes, vents, and other openings. Once inside, they may build nests anywhere it is cozy, such as the glove box, under the hood near the engine, in the trunk, near the spare tire, etc. If you think a vehicle may be infested by mice, take the follwoing steps to protect yourself:
- Open all vehicle doors and the hood of the car to air it out for at least 20 minutes before looking for signs of an infestation. Do not start the vehicle.
- Carefully inspect the vehicle for rodent nesting materials, droppings, and dead rodents while wearing gloves, goggles, a mask, and a long-sleeved shirt.
- Follow the cleaning instructions below.
Do not vacuum or sweep rodent droppings or nests. This can stir the virus into the air.
Instead:
- Wear rubber, latex, vinyl, or nitrile (synthetic rubber) gloves, an N-95 or P-100 respirator, vent-less goggles and disposable coveralls.
- Spray droppings and nesting materials with a household disinfectant or bleach solution
- Let it soak for at least 5 minutes
- Wipe up the area with paper towels
- Throw paper towels and debris in a trash bag, tie up and through away the trash bag as soon as possible.
- Double bag any dirty towels, rags, and/or dead rodents and place them in an air tight garbage can.
- Wash gloves with houseld disinfectant or soap and warm water before removing them, then wash hands thoroughly afterwards.
A bleach solution can be made by mixing 1 ½ cups household bleach with 1 gallon of cool water (or 1 part bleach to 9 parts water). Use only fresh solution.
Heavy Rodent Infestations: Special precautions should be used for cleaning areas with heavy rodent infestations (such as piled up droppings, numerous nests or dead rodents). More information on how to clean heavy rodent infestations can be found here. Homeowners should consider hiring a professional company to clean up areas with heavy rodents infestations.
Pet owners should consult their veterinarians about testing newly adopted rats fro hantaviruses before introducing them to a new home, especially if they will be living with other pets.
Keep wild rats (which naturally carry hantavirus) away from pet rats by taking steps to prevent rodent infestations.
Instructions for how to stay healthy and safely care for a pet rodent are found here: Small Mammals | Healthy Pets, Healthy People | CDC.
Information on how to protect yourself during the clean-up of heavy rodent infestation can be found here: Safely Cleaning Up After Rodents-Preventing Hantavirus Infection
What to do if you are exposed to rodents?
There is no test to determine if you have been exposed to hantavirus. The virus can only be detected with a blood test once symptoms appear.
If you have been exposed to rodents, you should monitor yourself for symptoms for up to eight weeks after the date of last exposure. If symptoms develop, seek medical attention, and inform your healthcare provider about the rodent exposure.